1. Field of the Invention
This invention relates to a progressive action, full extension drawer guide for cabinets, desks and the like wherein a series of roller guided rails are provided to allow the drawer to extend completely from a cabinet to allow full access to the rear portion of the drawer.
2. State of the Prior Art
Full extension drawer guides are well known and are used to permit full extension of drawers such that the back of the drawer is fully accessible. Such drawer guides usually use three or more rails with one rail (cabinet rail) being attached to the cabinet, one rail (drawer rail) being attached to the drawer and one rail (floating rail) gliding between the drawer and cabinet rails. Examples of such drawer guides are disclosed in the United States Pat. Nos. to Card, 1,537,067, Tobey, 2,099,148, Schaffert, 1,129,831, and Bullock et al, 3,203,749. In these systems, rollers or ball bearings are provided on racks between the floating rail and the cabinet and drawer rails to provide free gliding movement between each of the rails.
One of the problems associated with such systems is that they tend to be rather large and bulky which limits their use on smaller drawers. Further, such systems are relatively complicated and difficult to fabricate.
Another problem with such systems is that the floating rail in some systems (Card) does not move until the drawer rail is completely extended. Thus, the rail operation is a two-step process: the drawer rail is first fully extended, the floating rail is then contacted by a stop on the drawer rail and drawn to its fully extended position. This type of system is undesirable in that it provides a relatively rough operation of the drawer glide.
Some systems (Wolters) use a roller mounted on the floating rail to ride on tracks of the cabinet and drawer rail so that the floating rail moves one-half the distance of the drawer rail with respect to the cabinet rail. In this system, however, difficulty is encountered in maintaining the relationship between the three rails because of slippage between the wheels and the track. This results in misalignment of the three rails which causes rough operation at the ends of travel of the drawer. When misalignment occurs, the control roller provides frictional resistance between sliding of the cabinet and the floating rails, for example, when the drawer rail is fully extended or near its retracted position.